A Vitro Management of Four Tomato Fungal Pathogens Using Plant Extracts and Fermented Products

Abstract

Tomato, a popular vegetable crop, used in various dishes contains most of the essential nutritional requirements. It is the major commercial vegetable that can be grown throughout the country. Alternaria sp., Colletotrichum sp., Stemphylium sp. and Verticillium sp. are the important infectious causal agents that had threatened tomato. Regular use of chemical fungicides creates a hazardous effect to the environment and human health too. Fresh plant extracts and fermented products are easily available, easy to prepare, non hazardous to environment and human too. The organic compounds and secondary metabolites present in them are lethal to mycelia growth of these pathogens. Three wild plants (Agave cantula, Ageratina adenophora and Melia azeradach) are used for experimentation to control the mycelia growth of four tomato test pathogens in both form i.e. fresh extract and fermented form. Mancozeb (0.2mg/ml) used as positive control showed the reduction in mycelia growth of Alternaria sp., Colletotrichum sp., Stemphylium sp. & Verticillium sp. by 63.30%, 100%, 74.02% and 58.33% respectively. In the experiments, among three tested samples, both form of Agave cantula showed significant inhibitory effect to mycelia growth of three tomato pathogens v.i.z. Colletotrichum sp. (100% inhibition at 50% conc. of fresh extract and 100% inhibition at 60% conc. of ferment), Stemphylium sp. (83.33% inhibition at 60% conc. of fresh extract and 80.9% inhibition at 60% conc. of ferment) and Verticillium sp. (88.11% inhibition at 60% conc. of fresh extract and 88% inhibition at 60% conc. of ferment). Fresh extract and fermented product of A. cantula showed less inhibitory effect to the mycelia growth of Alternaria sp. (42.58% inhibition at 60% conc. of fresh extract and 44.29% at 60% conc. of ferment). It may be effective to A. solani at higher concentration.